This invention relates to a toy, and more particularly to improvements in a cartesian type of toy capable of being propelled in a controllable manner while submersed in a liquid such as water.
Small cartesian diving devices, designed to function in transparent chambers containing water and capable of being pressurized, are well known as toys for amusement purposes. The devices are generally constructed as bodies capable of undergoing changes in their volume in response to an applied hydrostatic pressure, thereby displacing a variable quantity of the suspending liquid, or as hollow bodies that admit or expel liquid in response to hydrostatic pressure to alter the weight of the body. In general, with increased pressure, the weight of the body becomes slightly greater than the weight of the liquid displaced thereby, causing a descending motion. With decreased pressure, the body becomes slightly lighter than the weight of displaced liquid, causing ascending motion.
While prior toys of this type have been amusing, they have not generally been endowed with movement capabilities other than straight descent and ascent. To secure and maintain a child's interest, other features of movement, functionality or controllability are necessary. Although prior efforts have been directed toward the development of cartesian toys of improved versatility, such toys have involved interactively moving components of generally intricate design. Toys of such construction are costly, unreliable, or demanding of frequent maintenance.
A preferred form of cartesian toy is a miniature submarine. One such embodiment, described in U.S. Pat. No. 2,402,081 is capable of ascent and descent movement, with a slightly inclined position being achievable during said movements. A highly desirable mode of action of a toy submarine would be controlled movement in a lateral plane, but this has not heretofore been successfully accomplished in a practical manner. Lateral movement of a cartesian toy has been disclosed for example in U.S. Pat. No. 3,382,606, but such mode of movement is achieved therein only by virtue of a propeller operated in conjunction with a complex multi-component device.
It is accordingly an object of the present invention to provide a cartesian toy of simple construction capable of controlled lateral movement in a liquid confined within a pressurized vessel. It is another object to provide a cartesian toy in the form of a submarine capable of controlled lateral movement in response to pressure variations applied to a liquid in which it is submersed. It is a still further object of the present invention to provide a cartesian toy in the form of a submarine having no moving parts and capable of ascent, descent and lateral movement in a liquid confined in a pressurized vessel, said movements being produced in response to pressure variations. These objects and other objects and advantages of the invention will be apparent from the following description.